classification and evolution

Question 1

what is classification

Answer 1

the name given to the process of sorting organisms into groups

Question 2

what are taxonomic groups

Answer 2

seven groups ordered in a hierarchy: kingdom, phylum,class,order,family,genus and species.

Question 3

how can you remember the order of the taxonomy groups

Answer 3

King Philip Came Over For Great Spagbowl

Question 4

what was later added to the taxonomy groups

Answer 4

Domain, this is added to the top of the hierarchy and was added due to the advancements in gene sequencing. they consist of Archea (70s ribosomes - RNA polymerase contain 8-10 proteins), bacteria (70s and 5 proteins in RNA polymerase) and eukarya (80s RNA has 12 proteins).

Question 5

why do we classify organisms

Answer 5

to see how closely related they are and find evolutionary links, to predict characteristics and identify a species

Question 6

what is a species. give the definition

Answer 6

a group of organisms that are able to breed to produce fertile offspring. if they cannot produce fertile offspring it is typically due to there being an odd number of chromosomes so they cannot undergo meiosis.

Question 7

what were the problems with the old methods of classification

Answer 7

they were not internationally agreed, species had more then one common name because of different languages, couldn’t tell evolutionary relationships.

Question 8

what is the binomial nomenclature. giev the rules for when writing like this.

Answer 8

a scientific name that consists of two parts. Genus species ie Homo sapiens (humans).

should be typed in italics or underlined if handwritten, lower case with the exception of the first letter of the Genus.

Question 9

what are the five kingdoms

Answer 9

prokaryote (bacteria) Protoctista (unicellular eukaryotes) fungi, plantae and animalia

Question 10

give some features of prokaryote

Answer 10

unicellular bacteria
no nucleus or membrane bound organelles
nutrients are absorbed through the cell wall, no visible feeding mechanism

Question 11

give some features of Protoctista

Answer 11

unicellular eukaryotes
nucleus and membrane bound organelles
have chloroplasts
nutrients are acquired via PHS or ingestions can be auto/heterotrophs

Question 12

give some features of fungi

Answer 12

uni or multicellular
cell wall made of chitin
no chloroplasts
have a body made of hyphae
saprophytic feeders - eat dead matter
store food as glycogen

Question 13

give some features of plantae

Answer 13

multicellular
contain chloroplasts
most dont move
autotrophs
store food as starch

Question 14

give some features of animalia

Answer 14

no chloroplasts
move with the aid of flagella or contractile proteins (muscles) store food as glycogen. are heterotrophs

Question 15

what is a recent chnage to classification

Answer 15

development of technology has allowed scientists to view DNA structures and discover links in evolutionary relationships. ie Hb in humans and chimpanzees is remarkably similar showing that there is an evolutionary link.

Question 16

what are the differences in Woese’s system

Answer 16

there are six kingdoms as the Prokaryotae is divided into Archaebacteria (live in extreme conditions, hot, thermal vents, anaerobic in acidic conditions) and eubacteria (peptidoglycan cell wall found in all environments)

Question 17

what is phylogeny

Answer 17

the name given to evolutionary relationships between organisms. it reveals which organisms are related to who and how closely.

Question 18

what are phylogenetic trees

Answer 18

a diagram used to represent relationships between organisms. the earliest species are found at the bottom of the tree and the recent species are found at the top of the tree. most of the evidence is gained from fossil fuels.

Question 19

give tips on how to interpret phylogenetic trees

Answer 19

closer the branches are the closer the evolutionary relationship, sister groups are when two descendants split from the same line.

Question 20

what are the advantages of phylogeny trees

Answer 20

continuous tree rather then discrete characteristics (not forced to put species in a group). it shows how long species have been around for (Linneaus implies that some species are of the same rank when this is not the case).

Question 21

what were darwins most famous observations

Answer 21

the finches in the galapagos islands. he noticed that different islands had different finches ,he concluded that they must be related as they were similar in many ways but had different beak and claw shape and sizes. he then founds that the shape of beaks was linked to the food available on each island.

Question 22

give three pieces of evidence for evolution

Answer 22

palaeontology - study fossil records
comparative anatomy
comparative biochemistry

Question 23

outline how fossils can be used as evidence of evolution

Answer 23

form when animal and plant reserves between rocks.

simple organisms such as bacteria and algae are found in the oldest rocks whilst more recent vertebrates are found in the recent rocks. showing that simple life gradually evolved into more complexed ones of extremely long periods of time.

plant fossils are found before animal fossils, this is consistent with the fact that animals need plants to survive.

fossils allow relationships to be investigated between extinct and current species.

however the fossil record is incomplete because some are undiscovered and commonly the wrong conditions for fossils to form.

Question 24

Give evidence for divergent evolution

Answer 24

a homologous structure is a structure that appears superficially different and may perform different functions but has the same underlying structure. ie pentadactyl limbs in vertebrates

the basic structure of all vertebrate limbs are similar ie to run to jump and to fly showing that limbs are adapted to lots of different functions so it is likely that they are evolved from one another. This is evidence of evolution

Question 25

what does the presence of homologous limbs give evidence of

Answer 25

divergent evolution - different species have evolved from a common ancestor due to habitat loss or migration and new selection pressures

Question 26

outline how comparative biochemistry can be used as evidence of evolution

Answer 26

similarities and differences in proteins and other molecules involved in life processes are highly conserved.

cytochrome C and ribsomal RNA can be used to test evolutionary relationships. the closer the match in the bases sequence of aa the more closely related the species are

Question 27

what is variation

Answer 27

the difference in characteristics between a organisms

Question 28

what is interspecific variation

Answer 28

ie a dog has 4 legs and a bird has 2 legs. variation between different species.

Question 29

what is intraspecific variation

Answer 29

differences between organisms within the same species. ie hair colour, skin colour, height.

Question 30

what causes variation

Answer 30

genetic material
environment

Question 31

outline how genetic variation is caused

Answer 31

we may inherit different alleles of a gene ie blood types A,B,AB and O.

mutations in somatic cells (just the individual affected) mutation of gametes ( the offspring are effected).

meiosis - random fusion of gametes, independent assortment and crossing over.

sexual reproduction - 2 parents inherrit half from mom and half from dad

Question 32

how does the environment effect variation

Answer 32

plants in the sun will grow larger then plants in the shade

scars ie you cannot inherit scars from your parents.

Question 33

give an example of a genetic and environmental variation

Answer 33

if you inherit alleles off your parents to be tall (mom and dad are both tall) but you have a poor diet during childhood you will never reach the height.

Question 34

what is discontinous variation

Answer 34

no in between values. ie animal sex, relies on genetic factors alone usually a single gene.

represented on a pie chart or bar chart graph

Question 35

what is continuous variation

Answer 35

height or weight. there is graduation in the values. controlled by lots of genes and the environment

plotted on a histogram and a curve is draw to show trend.

Question 36

what are adaptation

Answer 36

characteristics that increase a species likelihood of survival.
can be
anatomical - physical
behavioural - acts
physiological - inside

Question 37

give examples of anatomical adaptations

Answer 37

body covering (ie hair, fur, skin, feathers, shell) for protection, insulation or to fly. camouflage, teeth (carnivores have sharp to eat tough foods, herbivores have continuously growing molars to enable them to grind food down), mimicry - minicing other animals enables a species to fool predators into thinking that they are poisonous when in fact they are harmless.

Question 38

describe how maram grass is adapted to its environment

Answer 38

uit is a xerophyte, lives in an environment with little water availability.

rolled leaves to reduce SA

hairs on the inside surface of the leaf trap moist air to reduce the concentration gradient - less water lost by transpiration.

stomata is sunk into pits so less likely to open and lose water

thick waxy cuticle

Question 39

give some examples of behavioural adaptations

Answer 39

playing dead when spotted by a predator

to attract a mate they can perform a dance to increase the likelihood of reproduction

migration and hibernation help to cope with seasonal changes.

Question 40

what two categories can behavioural adaptations fall into

Answer 40

innate (something that you are born with)

learnt (through experiences and observations)

Question 41

what type of evolution do anatomical adaptions provide evidence for

Answer 41

convergent evolution. when unrelated species share similar traits due to similar environments and selection pressures. these are could analogous structures - adapted to perform the same function but have different genetic origin. ie tails and fins in whales and fish

Question 42

give three examples of physiological adaptations

Answer 42

poison production to kill prey or protect from being eaten
antibiotic production - some bacteria produce antibiotics to kill other bacteria in the surrounding area
water holding - storing in the body to prevent dehydration

Question 43

how are marsapian moles and placental moles evidence of convergent evolution

Answer 43

They both burrow to find worms and grubs, streamlined body shape, modified forelimbs for digging, velvety fur allowing movement through soil. yet they have different fur colour marsapian in white to orange where as placental is grey.

Question 44

give three modern examples of evolution

Answer 44

antibiotic resistance - selections pressure for bacteria is antibiotics killing them. a mutation occurs to prevent antibiotics killing them, they are more likely to outcompete bacteria with no antibiotic resistance. they are more likely to survive and reproduce passing on the useful alleles to their offspring. this leads to an increase in the advantages alleles changing the allele frequency in the population of bacteria.

peppered moths - pre industrial revolution moths were pale to camouflage against trees. during the IR the colour of tress darkened so being a darker coloured moth became a survival advantage as they were less likely to be spotted by predators

sheep bowflies - they lay there eggs in faecal matter around a sheeps tail, if left untreated it can be fatal. a pesticide to kill the blow flies lead to resistance 6 years later.

Question 45

describe the difference between analogous structures and homologous structures

Answer 45

AS - adapted to perform the same function but have a different genetic origin ie fins and tails of whales and fish
HS - appear superficially different but have the same underlying structure

Question 46

what is the name given to the evolution of a new species

Answer 46

speciation